Probiotics are known to help with human digestive health. Same theory applies to animals, no surprise here.
As a result of this, many cattle producers have begun transitioning to probiotics, which are also known as direct feed microbials (DFM). Unlike antibiotics, which are drugs which kill bacteria (both harmful and health-promoting ones) probiotics are live cultures of beneficial bacteria. By introducing them into an animal’s diet a cattle producer can, in theory at least, promote greater animal health and resistance to infection by replenishing the healthful bacteria in their cow’s gut.